JPH08145639A - Three-dimensional shape measuring apparatus for skin surface - Google Patents

Abstract

PURPOSE: To measure the three-dimensional shape of wrinkles on the surface of skin accurately and conveniently. CONSTITUTION: The apparatus for measuring the three-dimensional shape on the surface of skin comprises a knife-edge illumination means 1 for projecting a parallel light L to a skin surface S to form a dark and bright pattern thereon, means 2 for receiving the light projected from the knife-edge illumination means 1 and reflected on the skin surface S, a signal processing means for calculating the shape of the skin surface S based on the pattern of light received by the light receiving means 2, and means for shifting the knife-edge illumination means 1 and the light receiving means 2 integrally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a skin surface three-dimensional shape measuring apparatus. More particularly, the invention relates to an apparatus for measuring the three-dimensional shape of skin surface wrinkles using knife edge illumination.

[0002]

2. Description of the Related Art Various cosmetics have been developed to prevent or reduce wrinkles on the skin surface. However, for the purpose of objective evaluation of these effects or for the purpose of selecting a cosmetic suitable for the skin. As an index, it is necessary to directly and accurately measure the wrinkles on the skin surface.

[0003] Conventionally, as a method for measuring wrinkles, a method of collecting a replica of the skin surface using nitrocellulose, silicone rubber or the like and analyzing the surface shape by scanning with a stylus or a laser, the replica in one direction or There is known a method of analyzing a surface shape by performing image processing after illuminating from another direction and capturing an image.

As a method for directly measuring wrinkles, a method of directly imaging the skin surface and processing the image (direct skin analyze method) or projecting a strip-shaped pattern from a slit on the skin surface, There is known a method (light cutting method) of observing from a direction different from the projection direction and analyzing based on the degree of deformation of the pattern (light cutting surface) at that time.

[0005]

However, among the conventional methods, the method for collecting a replica of the skin surface is complicated in the operation of collecting the replica itself, and wrinkles cannot be easily measured in a short time. .

On the other hand, the image processing method for directly measuring wrinkles (direct skin analyze method) does not require the work of collecting a replica, and the time required for measurement can be shortened. Since various information such as pigment deposition is captured, it is difficult to accurately measure the surface shape based on the image. Further, in the light cutting method of projecting a band-shaped pattern from the slit on the skin surface and observing the deformed pattern according to the wrinkles of the skin, depending on the slit width and the surface shape of the skin, a missing portion may occur in the observation pattern, or Since it is difficult to accurately detect the edge line due to the overlapping of the patterns, it is difficult to accurately measure the surface shape of the skin in this case as well.

The present invention is intended to solve the problems of the prior art as described above, and an object thereof is to make it possible to directly and easily measure wrinkles on the skin surface directly.

[0008]

SUMMARY OF THE INVENTION In the light cutting method, the inventors of the present invention did not project slit light as in the prior art but instead projected a bright and dark pattern by knife edge illumination. Wrinkles on the skin surface can be accurately observed by observing the pattern (edge line) composed of the boundaries of the edges. In this case, by integrally moving the knife edge illumination and the light receiving part, workability during observation is greatly improved. This has led to the completion of the present invention.

That is, the present invention relates to (A) knife-edge illumination means for projecting parallel light that forms a light-dark pattern on the skin surface, and (B) light projected from the knife-edge illumination means and reflected on the skin surface. A light receiving means for receiving the light, (C) a signal processing means for calculating the shape of the skin surface based on the pattern received by the light receiving means, and (D) (A) a knife edge illumination means
(B) A skin surface three-dimensional shape measuring apparatus having a moving means for integrally moving the light receiving means.

In particular, (A) knife edge illumination projects light almost perpendicularly to the skin surface (projection angle about 0 °), and (B) light receiving means receives light at an angle of 30 ° to 50 °, more preferably about 45 °. A three-dimensional skin surface shape measuring device that receives reflected light from the skin surface is provided.

The present invention also provides a skin surface three-dimensional shape measuring method for measuring the surface shape of the skin using the above apparatus.

[0012]

In the device of the present invention, as shown in the principle diagram of FIG. 4, parallel light L that forms a light-dark pattern on the skin surface S is formed.
Is projected from the knife edge illumination means 1. The reflected light of the projected light forms a knife edge pattern (edge line) A of the light cutting surface as shown in FIG. Since the knife edge pattern A is deformed according to the uneven shape of the wrinkles of the skin, it is possible to measure the depth and shape of the wrinkles on the light cutting surface by observing this pattern from a direction different from the light projection direction. Become. In this case, there is no omission in the observation pattern due to the shape of the skin surface S as in the case of projecting a band-shaped pattern from the slit.

Further, by moving the knife edge illuminating means by the moving means, the projected light is scanned over a predetermined area of the skin surface, and the knife edge patterns observed thereby are aggregated, whereby the skin surface of the area is covered. It is possible to measure the three-dimensional shape of wrinkles. When the knife edge illumination means is moved and observed in this way, in the apparatus of the present invention, the knife edge illumination means and the light receiving means move integrally. Therefore, the knife edge pattern can always be satisfactorily observed without adjusting the light receiving means separately to adjust the light receiving position, and a sufficient measurement depth can be obtained over the entire measurement range on the face which is inherently complicatedly curved. It becomes possible to secure.

In particular, in the apparatus of the present invention, the projected light is made to enter the surface of the skin (the surface in the macro sense in which individual wrinkles on the surface are ignored) almost perpendicularly (projected angle about 0 °).
The reflected light from the skin surface is received at an acceptance angle of 30 ° to 50 °, more preferably about 45 °, and the knife edge illuminating means and / or the light receiving means or both 460.
By providing a filter that cuts the wavelength range of nm and above,
By reducing the effect of color reflection depending on the blood components under the skin, it is possible to greatly mitigate the reduction in the density difference of the knife edge pattern due to the internal diffused light of the skin, and thus it is possible to improve the measurement accuracy. .

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the drawings, the same reference numerals represent the same or equivalent constituent elements.

FIG. 1 is a schematic diagram of the apparatus of the present invention, and FIG.
Is an overall configuration diagram.

As shown in the figure, the apparatus of the present invention has a knife edge illumination means 1 and a light receiving means 2. The knife edge illuminating means 1 and the light receiving means 2 are integrally moved by a moving means composed of a moving stage 3 and a step motor 4 which fix them.

The knife edge illumination means 1 projects parallel light L so that a light and dark pattern is formed on the skin surface S, and the illumination tube 1a containing the knife edge light shielding means and the front surface thereof. The filter 1b is provided. Further, behind the knife edge lighting means 1,
As the slit light source 5, a halogen lamp that emits white light is provided.

A laser may be used as the light source 5 of the knife edge illumination means 1 from the viewpoint of the parallelism of the projected beam, but the object to be measured is the skin of the living body.
In particular, in many cases, considering that the vicinity of the outer corner of the eye adjacent to the eye is an observation target, the use of a laser poses a safety problem. Furthermore, existing lasers are limited to those with long wavelengths, and are therefore susceptible to color component-dependent color reflection.
Further, when laser light is used, the observed pattern flickers due to interference of reflected light on the skin surface, which makes it difficult to accurately detect edges. Therefore,
In the present invention, it is preferable to use a halogen lamp that emits white light, a metal halide lamp, or the like as in this embodiment.

Further, in this embodiment, the filter 1b
Is for reducing the contrast difference of the observation pattern due to the reception of diffused light from the inside of the skin by the light receiving means 2.
It is provided to cut off the high wavelength side of the white light emitted from the above-mentioned halogen lamp so as to suppress the reduction of the light and shade difference. As such a filter, one that cuts 460 nm or more is preferable.

On the other hand, the light receiving means 2 receives the reflected light from the skin surface, and includes the filter 2a and the lens system 2
b, a CCD camera section 2c. This filter 2a is provided for the same reason as the filter 1b of the knife edge illumination means 1. As the lens system 2b,
A telecentric optical system is preferable. Also,
The CCD camera section 2c is preferably formed of a CCD element having a sensitivity band in the short wavelength range.

The CCD camera unit 2 is provided after the light receiving means 2.
Signal processing means for calculating the shape of the skin surface based on the received light signal from c is provided. That is, the CCD-AMP unit 6 for amplifying the light reception signal from the CCD camera unit 2c, the signal processing device 7 for binarizing or ternarizing the light reception signal, the image capturing board (I / O) 8, the relative of each signal. A computer 9 for calculating the surface shape based on the statistical deviation,
A CRT 10 for displaying the calculation result of the wire frame image and the like by the computer 9 is provided.

In the apparatus of this embodiment, since the knife edge illumination means 1 and the light receiving means 2 are both fixed to the moving stage 3 as described above, they are integrally moved by the action of the step motor 4. To do. Here, the step motor 4 is controlled by the personal computer 9 via the I / O board 11 and the motor driver 12.

Therefore, in order to measure the predetermined area of the skin surface, the step motor 4 is operated so that the light projected from the knife edge illumination means 1 scans the predetermined area of the skin surface, and the reflected light is When light is received by the light receiving means 2, even if the position of the light receiving means 2 is not specially adjusted according to the position of the knife edge illumination means 1,
It becomes possible to make the reflected light enter the substantially central portion of the light receiving means 2. Therefore, as shown in FIG. 3A, the edge line A, which is the light-dark boundary of the knife edge pattern formed on the basis of the received light, is always set at the CRT 10
It is possible to position it in the center of the screen. This also makes it possible to increase the measurement depth. On the other hand, when the light receiving means 2 is not moved integrally with the knife edge illumination means 1, the edge line A is displayed on the screen according to the position of the knife edge illumination means 1 as shown in FIG. Therefore, there is a problem in that the measurement depth becomes shallower and the measurement may not be performed. In particular, when the measurement target is a three-dimensional surface that is inherently complicatedly curved like a face, such a problem becomes remarkable.

Also, in this apparatus, an angle adjusting mirror 13 is fixedly provided on the moving stage 3 for adjusting the angle of the measuring light incident on the light receiving means 2.

In the present invention, the light projection angle to the skin surface and the light reception angle of the reflected light from the skin surface are not particularly limited, but as shown in FIG. 1, the projected light is incident on the skin surface S substantially vertically. It is preferable that the reflected light from the skin surface is received at the light receiving angle θo = 30 ° to 50 °, more preferably θo = about 45 °. Generally, since the skin is a translucent body, internal diffusion of the projected light is likely to occur, which reduces the difference in shade of the knife edge pattern to be measured, and the measurement accuracy is likely to decrease, but the projection angle θi is 0 °. Since the ratio of the diffused light inside the skin in the reflected light can be reduced as the value becomes closer to, it is possible to suppress the reduction in the density difference of the knife edge pattern and improve the measurement accuracy, which is preferable. Regarding the light receiving angle θo, the received light is 9
As the wrinkle unevenness is more likely to be detected as it approaches 0 °, the wrinkle measurement accuracy is improved, but if the angle is too large, a blind spot occurs and a missing data point occurs. When the angle θi is approximately 0 °, the light receiving angle θo is preferably 30 ° to 50 °, more preferably about 45 °.

When measuring wrinkles on the skin surface using the above apparatus, considering the influence of human body movements such as fluctuations of the human body, movements of the eyeball, and heartbeat on the measurement,
It is preferable to complete the measurement in the shortest possible time. Since it is preferable that the entire contour of the skin surface is not extremely curved within the range, the measurement range is appropriately determined according to the contour of the measurement site and the like. Further, the measurement magnification can be appropriately determined according to the degree of wrinkles, but usually it can be about 10 to 100 times for the measurement of facial wrinkles.

As a specific measurement mode, for example, the distance between the knife edge illumination means and the skin surface to be measured is about 26.
mm and setting the lens magnification and the measurement range as in Modes 1 to 6 shown in Table 1, the measurement is completed in 4.5 to 15 seconds, and the xy direction (skin surface direction) resolution 1
It was possible to achieve 2.5 to 30 μm, measurement depth 9 to 21 mm, and z-direction (depth direction) resolution 17.6 to 41 μm. Then, for example, based on the measurement result of the deep wrinkles on the outer corners of the eyes, the wire frame diagram as shown in FIG.
I was able to display it on T.

[0029]

[Table 1] Mode: 1 2 3 4 5 6 Lens magnification: 10 10 50 50 50 50 XY measurement range (mm) X: 15 20 6.4 12.8 20 20 (mm) Y: 15 15 6.4 6.4 6.4 6.4 XY resolution (μm ) ΔX: 30 30 12.5 12.5 12.5 25 (μm) ΔY: 30 30 12.5 12.5 12.5 12.5 Measuring depth (mm) Z: 21 21 9.0 9.0 9.0 9.0 Depth resolution (μm) ΔZ: 41 41 17.6 17.6 17.6 17.6 Measuring time (sec) ): 4.5 6.5 5 10 15 7.5

[0030]

According to the present invention, the three-dimensional shape of wrinkles on the skin surface can be easily and accurately measured.

[Brief description of drawings]

FIG. 1 is a schematic diagram of the device of the present invention.

FIG. 2 is an overall configuration diagram of the device of the present invention.

FIG. 3 is an explanatory diagram of a knife edge pattern.

FIG. 4 is an explanatory view of the principle of a light cutting method using knife edge illumination.

FIG. 5 is a wire frame diagram of the outer corner of the eye.

[Explanation of symbols]

 1 knife edge illumination means 1a illumination tube 1b filter 2 light receiving means 2a filter 2b lens system 2c CCD camera section 3 moving stage 4 step motor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location G06T 7/00 1/00 G06F 15/64 M (72) Inventor Shuichi Akasaki Hanamigawa-ku, Chiba City, Chiba Prefecture 1-3-2 Asahigaoka-cho (72) Inventor Michio Kawai 2-9-2-101 Yamate, Funabashi City, Chiba Prefecture

Claims (6)

[Claims] 1. (A) Knife edge illumination means for projecting parallel light that forms a light-dark pattern on the skin surface, (B) Light reception for receiving light projected from the knife edge illumination means and reflected by the skin surface Means, (C) signal processing means for calculating the shape of the skin surface based on the pattern received by the light receiving means, and (D) (A) knife edge illumination means and (B) moving the light receiving means integrally A skin surface three-dimensional shape measuring apparatus characterized by having a moving means. 2. The three-dimensional skin surface shape measuring apparatus according to claim 1, wherein the (A) knife edge illumination means comprises a light source that emits white light and a knife edge light shielding means. 3. A wavelength of 460 for (A) knife edge illumination means
The skin surface three-dimensional shape measuring apparatus according to claim 2, further comprising a filter that cuts nm or more. 4. The three-dimensional skin surface shape measuring apparatus according to claim 2 or 3, wherein (B) the light receiving means is provided with a filter for cutting wavelengths of 460 nm or more. 5. The knife edge illumination (A) projects light substantially perpendicularly to the skin surface, and the light receiving means (B) receives reflected light from the skin surface at a light receiving angle of 30 ° to 50 °. 3. The skin surface three-dimensional shape measuring device according to any one of 1. 6. A skin surface three-dimensional shape measuring method for measuring the surface shape of skin using the apparatus according to claim 1.